feat: use browser context #138

This feature uses puppeteer.BrowserContext for the convertion tasks. Now, not for each task, an own browser instance is instantiated, but only one. This one and only is used, and only browserContexts are passed down to the convertion functions. Reduces CPU Load, eliminates EventEmitter warnings and speed up conversion of large amount of files by ~50%.
simonhaenisch · Nov 3, 2022 · fccf275 · fccf275
1 parent e51c3b6
commit fccf275
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Showing 4 changed files with 24 additions and 14 deletions.
diff --git a/src/cli.ts b/src/cli.ts
@@ -10,6 +10,7 @@ import getPort from 'get-port';
 import getStdin from 'get-stdin';
 import Listr from 'listr';
 import path from 'path';
+import puppeteer from 'puppeteer';
 import { PackageJson } from '.';
 import { Config, defaultConfig } from './lib/config';
 import { help } from './lib/help';
@@ -64,6 +65,7 @@ main(cliFlags, defaultConfig).catch((error) => {
 
 async function main(args: typeof cliFlags, config: Config) {
 	setProcessAndTermTitle('md-to-pdf');
+	const browser = await puppeteer.launch({ devtools: config.devtools, ...config.launch_options });
 
 	if (!validateNodeVersion()) {
 		throw new Error('Please use a Node.js version that satisfies the version specified in the engines field.');
@@ -125,25 +127,28 @@ async function main(args: typeof cliFlags, config: Config) {
 	 */
 
 	if (stdin) {
-		await convertMdToPdf({ content: stdin }, config, args)
+		const stdContext = await browser.createIncognitoBrowserContext();
+		await convertMdToPdf({ content: stdin }, config, args, stdContext)
 			.then(async () => closeServer(server))
 			.catch(async (error: Error) => {
 				await closeServer(server);
-
 				throw error;
 			});
 
+		await browser.close();
+
 		return;
 	}
 
+	const listrContext = await browser.createIncognitoBrowserContext();
 	const getListrTask = (file: string) => ({
 		title: `generating ${args['--as-html'] ? 'HTML' : 'PDF'} from ${chalk.underline(file)}`,
-		task: async () => convertMdToPdf({ path: file }, config, args),
+		task: async () => convertMdToPdf({ path: file }, config, args, listrContext),
 	});
 
 	await new Listr(files.map(getListrTask), { concurrent: true, exitOnError: false })
 		.run()
-		.then(() => {
+		.then(async () => {
 			if (args['--watch']) {
 				console.log(chalk.bgBlue('\n watching for changes \n'));
 
@@ -155,6 +160,7 @@ async function main(args: typeof cliFlags, config: Config) {
 					new Listr([getListrTask(file)], { exitOnError: false }).run().catch(console.error),
 				);
 			} else {
+				await browser.close();
 				server.close();
 			}
 		})

diff --git a/src/index.ts b/src/index.ts
@@ -1,6 +1,7 @@
 #!/usr/bin/env node
 
 import getPort from 'get-port';
+import puppeteer from 'puppeteer';
 import { Config, defaultConfig, HtmlConfig, PdfConfig } from './lib/config';
 import { HtmlOutput, Output, PdfOutput } from './lib/generate-output';
 import { getDir } from './lib/helpers';
@@ -50,7 +51,9 @@ export async function mdToPdf(input: Input, config: Partial<Config> = {}): Promi
 
 	const server = await serveDirectory(mergedConfig);
 
-	const pdf = await convertMdToPdf(input, mergedConfig);
+	const browser = await puppeteer.launch({ devtools: config.devtools, ...config.launch_options });
+	const md2pdfContext = await browser.createIncognitoBrowserContext();
+	const pdf = await convertMdToPdf(input, mergedConfig, undefined, md2pdfContext);
 
 	server.close();
 

diff --git a/src/lib/generate-output.ts b/src/lib/generate-output.ts
@@ -16,15 +16,16 @@ interface BasicOutput {
 	filename: string | undefined;
 }
 
+interface GenerateOutputProps {
+	html: string;
+	relativePath: string;
+	config: PdfConfig | HtmlConfig | Config;
+	browser: puppeteer.BrowserContext;
+}
 /**
  * Generate the output (either PDF or HTML).
  */
-export async function generateOutput(html: string, relativePath: string, config: PdfConfig): Promise<PdfOutput>;
-export async function generateOutput(html: string, relativePath: string, config: HtmlConfig): Promise<HtmlOutput>;
-export async function generateOutput(html: string, relativePath: string, config: Config): Promise<Output>;
-export async function generateOutput(html: string, relativePath: string, config: Config): Promise<Output> {
-	const browser = await puppeteer.launch({ devtools: config.devtools, ...config.launch_options });
-
+export async function generateOutput({ html, relativePath, config, browser }: GenerateOutputProps): Promise<Output> {
 	const page = await browser.newPage();
 
 	// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
@@ -65,7 +66,5 @@ export async function generateOutput(html: string, relativePath: string, config:
 		outputFileContent = await page.pdf(config.pdf_options);
 	}
 
-	await browser.close();
-
 	return config.devtools ? (undefined as any) : { filename: config.dest, content: outputFileContent };
 }
diff --git a/src/lib/md-to-pdf.ts b/src/lib/md-to-pdf.ts
@@ -1,6 +1,7 @@
 import { promises as fs } from 'fs';
 import grayMatter from 'gray-matter';
 import { dirname, resolve } from 'path';
+import puppeteer from 'puppeteer';
 import { Config } from './config';
 import { generateOutput } from './generate-output';
 import { getHtml } from './get-html';
@@ -17,6 +18,7 @@ export const convertMdToPdf = async (
 	input: { path: string } | { content: string },
 	config: Config,
 	args: CliArgs = {} as CliArgs,
+	browser: puppeteer.BrowserContext,
 ) => {
 	const mdFileContent =
 		'content' in input
@@ -87,7 +89,7 @@ export const convertMdToPdf = async (
 
 	const relativePath = 'path' in input ? resolve(input.path).replace(config.basedir, '') : '/';
 
-	const output = await generateOutput(html, relativePath, config);
+	const output = await generateOutput({ html, relativePath, config, browser });
 
 	if (!output) {
 		if (config.devtools) {